1. Field of the Invention
The present invention generally relates to a cache-injection enabled computer system, and more particularly, to a cache-line based notification in such computer systems.
2. Prior Art
Today's computer systems offer more and more processing cores in order to increase the performance of the system as a whole, while the single-core performance almost stays the same. However, it is not yet clear how to use the new resources efficiently. One approach is, for example, on-loading of tasks that were formerly off-loaded to dedicated devices, for example, the network packet processing. In order to cope with the increasing needs in packet processing, concepts have been developed that take advantage of the use of dedicated cores for network packet processing. Those concepts may use a doorbell mechanism, which is a mechanism used to notify a process or application that a new request is available. This mechanism can so far not be implemented efficiently in software.
Some processors today offer the possibility to wait on a cache-line (CL) modification of the local cache and use it as a wake-up instruction. This mechanism is especially efficient in multi-threaded processing units. On the other hand, this mechanism can only be used for one single cache-line, so either the serving process only gets a single doorbell cache-line, which is not practical for multi-user serving, or the serving process has to know exactly where the next request will arrive, which is again not possible in many-to-one communication situations.